STUDY DESIGN: The research was designed as a crossover, randomized control trial.
MATERIALS AND METHODS: Subjects comprised patients receiving fixed appliances at a teaching institution and indicated for VFRs. Post-treatment stone models were scanned with a structured-light scanner. A fused deposition modelling machine was used to construct acrylonitrile-butadiene-styrene (ABS)-based replicas from the 3D scanned images. VFRs were fabricated on the original stone and printed models. Analysis comprised independent t-tests and repeated measures analysis of variance.
RANDOMIZATION: Subjects were allocated to two groups using Latin squares methods and simple randomization. A week after debond, subjects received either VFR-CV first (group A) or VFR-3D first (group B) for 3 months, then the interventions were crossed over for another 3 months.
BLINDING: In this single-blinded study, subjects were assigned a blinding code for data entry; data were analysed by a third party.
OUTCOME MEASURES: The primary outcome measured was oral health-related quality of life (OHRQoL) based on Oral Health Impact Profile-14 (OHIP-14). Secondary outcome was post-treatment stability measured using Little's Irregularity Index (LII).
RESULTS: A total of 30 subjects (15 in each group) were recruited but 3 dropped out. Analysis included 13 subjects from group A and 14 subjects from group B. Group A showed an increase in LII (P < 0.05) after wearing VFR-CV and VFR-3D, whereas group B had no significant increase in LII after wearing both VFRs. Both groups reported significant improvement in OHRQoL after the first intervention but no significant differences after the second intervention. LII changes and OHIP-14 scores at T2 and T3 between groups, and overall between the retainers were not significantly different. No harm was reported during the study.
CONCLUSION: VFRs made on ABS-based 3D printed models showed no differences in terms of patients' OHRQoL and stability compared with conventionally made retainers.
REGISTRATION: NCT02866617 (ClinicalTrials.gov).
MATERIALS AND METHODS: An electronic search of the scientific literature from January 2005 to June 2016 was done using Web of Science, Dentistry & Oral Sciences Source and PubMed databases. A combination of search terms "rapid maxillary expansion", "nasal", "airway" and "breathing" were used. Studies that involved surgical or combined RME-surgical treatments and patients with craniofacial anomalies were excluded.
RESULTS: The initial screening yielded a total of 183 articles. After evaluation of the titles, abstracts and accessing the full text, a total of 20 articles fulfilled both inclusion/exclusion criteria and possessed adequate evidence to be incorporated into this review.
CONCLUSIONS: Non-surgical RME was found to improve breathing, increase nasal cavity geometry and decrease nasal airway resistance in children and adolescents.
HIGHLIGHT: There were conflicting results regarding sexual dimorphism and population characterization of the palatal rugae patterns. All rugae showed positional changes, increased lengths, and lower numbers, but no significant shape changes with growth. The lengths, numbers, and positions of the rugae were affected by orthodontic treatment, especially their lateral points, but their individual characteristics did not change.
CONCLUSION: The diversity in rugae patterns and their potential for sex discrimination among different populations showed differing results due to individual variations and the complex influence of genetic, growth, and environmental factors on their morphology.
METHODS: Data consisted of pre- and post-treatment lateral cephalograms of 95 children, 49 patients with RTB and 46 patients with RPFM, divided into an early (8-9 year) and late (10-11 year) group. Treatment changes were assessed by the Ricketts analysis using CASSOS software, where 71 anatomic landmarks were identified in each cephalogram. Paired and independent t tests were performed for statistical comparison.
RESULTS: Paired t test revealed significant changes in facial axis, facial angle, MD plane to FH, lower facial height, mandibular arc, maxillary convexity, U1 to APog, L1 to APog, L1 to APog angle and upper lip to E-plane measurements in RPFM, whereas significant changes were found in facial taper, U1 to APog and lower lip to E-plane values with RTB in the early treatment group. Independent t test revealed significant changes in U1 to APog, L1 to APog and U6 to PtV values in the RTB group. Post-treatment comparison of RTB and RPFM showed significant differences in L1 to APog and L1 to APog angle values.
CONCLUSIONS: RPFM revealed more favourable craniofacial changes than RTB, particularly in the late mixed dentition stage.